Half to joseph w



(No Model.) 7 3 Sheets-Sheet 1; W. S. McKENNA.

METALLURGICAL FURNAOE.

Patented Feb. 2, 1897.

(No Model.) 3 Sheets-Sheet 2,

W. S. MOKENNA. METALLURGICAL FURNACE.

Nb. 576,323. A Pate nted Feb.2,189 7.

. i w 24.... JWM I [EM-1K 3 Sheets Sheet 3.

(No Model.)

w. s. MOKENNA. METALLURGICAL FURNACE.

"Patented Feb 2, 1897.

fiveirfor: wmdww W WVILLIAM S. MCKENNA, OF PITTSBURG ATENT OFFICE.

,IPENNSYLVANIA, ASSIGNQR on ONE- HALF TO JOSEPH XV. KEFFER, OF SAME PLACE.

METALLURGICAL FURNACE.

SPECIFICATION forming part of Letters Patent No. 576,323, dated February 2, 1897.

Application filed June 22, 1896. Serial No. 596,525. (No model.)

To all whom it may concern.-

Be it known that 1, WILLIAM S. MCKENNA, a resident of Pittsburg, in the county of Allegheny and State of Pennsylvania, have invented a new and useful Improvement in Metallurgic Furnaces; and I do hereby declare the following to be a full, clear, and exact description thereof.

My invention relates to furnaces for heating what are commonly called pairs and packs, in connection with the manufacture of sheet-iron.

The object of my invention is to construct such a furnace with flues arranged in such a manner as to obtain the greatest amount of heat for the amount of fuel used, and largely reduce the cost of manufacture. My invention therefore comprises certain details of construction, all of which will be fully hereinafter set forth and claimed.

To enable others skilled in the art to make and use my invention, I will describe the same more fully, referring to the accompanying drawings, in which Figure 1 is a longitudinal vertical section of my improved furnace. Fig. 2 is a section 011 the line 2 2, Fig. 1. Fig. 3 is a front view; and Fig. 4. is a section on the line 4 4, Fig. 2.

Like letters of reference indicate like parts in each.

In the accompanying drawings the letter a designates the walls of the furnace, which are constructed of brick, and which may be braced and held together in any suitable manner. At one end of the furnace is a pair-heating chamber 1), which has the floor b, adapted to receive the metal. The pairheating chamber is provided with the charging-doors b and the air-inlet If. This airinlet 12 is provided with the swinging door b said door having the chains 6 connected thereto,which pass over pulleys b", said chains having the weights 1) attached thereto. Leading from the bottom of the pair-heating chamber are the lines c, said flues extending up and communicating with a common flue 0', extending along the top of the furnace and communicating with the chimney (l. Beneath the floor b of the pair-heating chamber 17 is the air-heating chamber e, which is in direct communication with the atmosphere.

At'the other end of the furnace is the sheetheating chamber f, said chamber having the inclined fioor f, made up of tiles of suitable dimensions. The sheet-heating chamber fis provided with the charging-door f adapted to slide up and down in suitable guides, and which has the chains f connected thereto passing up over the pulleys said chains having the weights f attached thereto. The to floor f of the sheet-heating furnace is supported by the partitions g, which divide the space beneath said floor into separate chambers 9. These chambers g are in communication with the sheet-heating chamber f through the openings 9* adjacent to the charging-door f The opening h, leading to the several chambers g below the floor f of the sheet-heating chamber, is provided with the door h,which is hinged at the top and adapted to swing from that point. Leading from the space below the floor f and communicating with the several chambers g" are the flues 'i, which pass up through the walls of the furnace and communicate at their upper ends with the chimney.

Intermediate of the pair-heating chamber Z) and sheet-heating chamber f is the firechamber 70, said fire-chamber being provided with the grate-bars is, beneath which is the ash-pit 7c. The doors 10 close the opening leading to the ash-pit 78. The ash-pit k is also provided with the air-inlet 70*, and the plate k having openings'k therein. permits air to enter above the grate-bars. The firechamber 7; is provided with a suitable stoking-hole Z. A fire-bridge on extends up between the fire-chamber and the pair-heating chamber. The fire-chamber 7c is in commu nication with the pair-heating chamber b, and 0 by means of the flue 02 also in communication with the sheet-heating chamber f. This flue "a is formed by the bridge 0, which separates the fire-chamber from the sheet-heating chamber, said bridge 0 having the forwardly-projecting arch 0. The line or is thus formed between the upper face of the arch o and the top of the furnace. This bridge 0 has the air-. passage 0 formed therein, said air-passage being in communication with the lines 19, which lead from the air-space e to said passage, said flues being formed in the side walls of the furnacc. In this manner the air which passes through the tines 19 around the fire-box is highly heated, and when discharged from the passage 0 into the sheet-heating chamber at the point where the products of combustion coming through the flue It meet said highlyheated air a very high heat in the sheet-heating chamber results, while at the same time a more perfect combustion is obtained.

The steam-pipe 0 has the branches r 1- r connected thereto. The branch pipes r,which are located within the flue 0, when emitting steam create a draft-through the pair-heating chamber, said branch pipes having the ends 0' longitudinal of said flue c, and with the outlets in the direction of the chimney d. The branch pipes r projecting straight down within the flue 0 when emitting forth steam, act as a damper and practically close off the draft through the pair-heatin g chamber to the chimney d. The branch pipe 1' has the vertical end 7"", which projects up within the chimney, and when emitting forth steam creates adraft through the sheet-heating chamber and up the lines 1 to the chimney (Z. These branch pipes are all provided with suitable valves 5.

\Vhen the furnace is in use, it is operated in the following way: Fire is started in the firechamber, and when the furnace has been raised to the proper heat both the pairheating chamber and the sheet-heating chamber may be charged with bars and sheets, respectively. It is customary to allow the bars or billetsin the pair-heatin g chamberto soak, as it is commonly termed, until they have been raised to a high temperature. To accomplish this, the valve leading to the branch pipes r is opened, so that said branch pipes emit the steam into the line a. This cuts off the draft and the heat is retained within the pair-heating-chamber until the bars or billets have been raised to the proper temperature. The steam is then shut off from the branch pipes r and the valves of the branch pipes r are then opened to allow the steam to escape through the ends 1- This creates a draft through the pair-heating chamber 1) by means of the dues c c to the chimney d. As the products of combustion from the fire-chamber pass over the bridge-wall on they are sent to the top of the pair-heating chamber and are then compelled to descend to the bottom thereof in order to escape by the flue c. In this manner the heat is allowed to circulate thoroughly throughout the chamber before it makes its escape. As the heat ascends through the flue c it passes into the flue c,which is directly over the pair-heating chamber and is only separated from the same by the roof of said chamber. In this waythe escaping heat is utilized to further heat the pair-heatin g chamber. At the same time the sheet-heating chamber f, having been charged with packs, the steam is allowed to escape from the ends r of the pipes W. This creates a draft through the sheet-heating chamber f, the course of the draft being from the fire-chamber up over the wall 0, through the fine a into the chamber f, thence down through the openings g into the fines g and thence up through the fines t' to the chimney d. Highly-heated air is constantly admitted to the sheet-heating chamber f by means of the air-fines p, which communicate with the passage 0 of the bridge 0. In this way the products of combustion coming from the firechamber and the highly-heated air meet at about the middle of the sheet-heating chamber and create an intense heat. The slanting hearth of the sheet-heating chamber and the projecting arch oaet to form a chamber Which is deep at the inner end of the sheetheating chamber, but which has a contracted opening due to the slanting of the hearth. In this manner the highly-heated products of combustion are held within the sheet-heatin g chamber before they are permitted to escape through the openings The bridge-Wall o and the arch 0 become highly heated and the heat is radiated onto the packs, so that in this Way all the heat is utilized. Air may also be admitted to the fire-chamber through the opening 75 said air passing up through the grate-bars and also up through the openings 7;.

What I claim as my invention, and desire to secure by Letters Patent, is-

A furnace for heating metals having a pairheating chamber and a sheet-heating chamber, a fire-chamber intermediate of said chambers, bridge-walls separating said fire-chamber from said chambers, an arch extending into the sheet-heatin g chamber from the upper end of the bridge-wall separating said chamber from the fire chamber, said pairheating chamber having a flue leading from the bottom thereof to a flue just above the top of said furnace, said pair-heating chamber and sheet heating chamber communicating with a common chimney, substantially as set forth.

In testimony whereof I, the said \VILLIAM S. MCKENNA, have hereunto set my hand.

\VILLIAM S. MCKENNA.

Witnesses:

RoBr. D. TOTTEN, ROBERT C. TOTTEN. 

